Fire alarm



Aug. 14, 1951 J SFREDDO 2,563,877

FIRE ALARM Filed Aug. 22, 1949 2 Sheets-Sheet 1 Fig. v Fig.2.

I n L'entar John Sfredda gwwm;

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Aug. 14, 1951 Filed Aug. 22, 1949 J. SFREDDO FIRE ALARM W Sheets-Sheet 2Fig. 4.

/2 Inventor John .Sfredda 82 H a r I mu way 1?. Mia? Patented Aug. 14,1951 UNITED STATES PA'ITHENT OFFICE FIRE ALARM John Sfrcddo, River Edge;N. J.

Application August 22, 1949, Serial No. 111,603

Claims. 1

This invention relates to fire alarms, and: more particularly toimprovements in the temperature responsive operating means for actuatingthe audible sound producing element of the alarm.

An object of this invention is to awaken and warn sleeping people of thepresence of a fire.

Another object of this invention is to provide a simple and compactapparatus which will give an alarm having sufficient volume and durationto give ample warnin of the peril of fire.

Afurther object is to devise improved actuating mechanisms for operatingthe audible sound producing element of the alarm.

A yet further object is to provide a spring wound temperature controlledalarm which will include a novel and improved construction forindicating when the alarm is set for operation and when it is run down.

A still further object is to provide a temperature responsive alarmincluding sound producing means operatively connected to a spring drivenmechanism, novel and improved means for retaining the spring fromactuating said sound producing means, and a thermostat independent ofsaid spring allowing said sprin driven mechanism to actuate the soundproducing means at a selective temperature range.

These together with various additional objects of the invention, whichwill later become apparent as the following description proceeds, areattained by this fire alarm, the preferred embodiment of which has beenillustrated by way of example only in the accompanying drawings,wherein:

Figure 1 is a front elevational view of the preferred embodiment of: thefireialarm Figure 2 is a rear elevational View;

Figure 3 is a vertical cross sectional view as taken along line 3-3 inFigure l;

Figure 4 is a horizontal cross sectional view taken along line 404 ofFigure 1;

Figure 5 is an elevation View of a portion of the device of Figure 1showing in greater detail portions of the spring means of the actuatingmechanism;

Figure 6 is an elevational view, parts being shown in section, of thespring driven mechanism adapted to be used with the spring means shownin Figure 5;

Figure 7 is a view of parts of the temperature responsive portion of thepresent device;

Figure 8 is an elevational view of other parts of the temperatureresponsive portion showing the position of the thermostat in greatestdetail; and,

Figure 9 is an enlarged view of the catch: used in the present firealarm.

Referring now more particularly to the accompanying drawings whereinlike numerals designate similar parts throughout the various views,attention is directed first to Figures 1-3 wherein the principle of thepresent invention is most clearly shown in the preferred embodiment.Reference numeral Ill generally denotes the fire alarm comprising thepresent invention and having a base l2 with a stand [4 pivotally securedthereto. The base 12 has an aperture IS in its upper portions.cylindrical side walls It and rear wall 20 is secured to the base I2over the aperture 6 by means of screws or the like. A shaft 22 isjournalled in the rear wall 20' of the container and its inner endextends intothe aperture It. A key or knob 23 is secured to the innerend of shaft 22.

A sprin 24 coaxial with the shaft 22' is secured at one end to the shaftmedially thereof. The other end of the spring is secured to a post 26attached to the rear wall 20 adjacent the side wall i8. Pivotallysecured on the post is an indicating marker comprising an arm 28 and abutton 30. A slit 32 is angularly cut in the side wall I8 which thebutton 32 is adapted to" pass through. Upon release and expansion of thespring 24 by means to be henceforth disclosed, the adjacent coil of thespring will: press the button outwards of the slit 32. When the springis wound by the key or knob 23, the button will fall within thecontainer by force of gravity alone. Secured to the outer end of theshaft 22 is a sprocket wheel 36.

Referring now more particularly to Figures 3 and 6, it will be seen thata cover comprising a front wall 38 and cylindrical side wall 40 is inalignment with and adapted to be secured to the side walls l8 of thecontainer. A siren or other sound-producing device 42 is secured to thefront wall 38 of the cover and has its drive shaft 4! having a drivegear 46 secured thereonextend within the cover. Journaled; on the coverbelow the drive gear 46 are pinion contact gear 48 and transmitting gear5!! adapted and positioned to engage sprocket wheel 36 and drive gear46, respectively. The side wall 40 of the cover has an aperture 52therein for a purpose to be described in the succeeding portions of thespecification.

Below the gear train assembly previously described, a shaft 54 isjournaled in a housing 56 and a circular plate 58 is rotatably securedon A container having the shaft 54 at its innermost end. As shown bestin Figure '7, the plate 58 has a pair of opposed, elongated, arcuateapertures 60 and 62. The housing 56 comprises a cylindrical side wall 64having flanges 66 inturned at the outmost end thereof, and an indicatingplate 68 secured intermediate the ends of the side wall 64. Suitablymounted within the hOllSiIlg 56 is a magnet adapted to becomeselectively aligned with an aperture 60 or 62 in the plate 58. On theother side of the plate 58 and opposed to the magnet 10 is a disksurface 12 of a catch member designated by reference numeral 14. Thedisk 12 is constructed of a magnetic metal while the plate 58 is made ofa light-weight non-magnetic material such as aluminum or magnesium. Thediameter of the disk I2 is substantially the width of the apertures 60and 62 and the disk 12 is adapted to pass through an aperture andcontact the magnet under certain specified conditions.

A spring thermostat 16 is provided having its ends terminally secured tothe shaft 54 and the Wall 64. A glass cover 18 is secured between theflanges 66 and an annular gasket 80. Suitable indicative reference marksare positioned on the indicating plate 68 as shown in Figure 1 andsuitable reference marks are placed on the inner end of the side wallsas shown in Figures 7 and 8. A referenc arrow is positioned adjacent theaperture 60 on the plate 58. The housing is hinged as at 82 for openingand inspection, and latching means, shown at 84, is provided to securethe housing in operative position.

The catch 14, as shown best in Figures 3 and 9, comprises the disk 12having a stem 86 threaded into the leg 88 of the catch 14 extendingdownwardly from the central portion 90. The central portion 90 isslidably held by bearings 92 mounted on the side wall 64, and terminatesin an angular cam surface 93. An upwardly extending, angularly divergentrelease stop arm 94 is engageable with the cam surface 93 of the catch14 and is adapted to engage the transmitting gear 50.

The operation of the device is as follows: The key 23 is wound totension the spring 24 which allows the re-set button 30 to fall throughthe aperture 32.

The disk 12 is removed from contact with the magnet 10 by a slightfinger pressure on the cam surface 93 of the catch.

The plate 58 is rotated on the shaft and secured thereto with the arrowadjacent the aperture 60 indicating a selective operating temperature asseen on the side wall 64.

At the set temperature, the aperture 60 will be in alignment with themagnet 10 and the disk 12 will be drawn therethrough. The release stoparm will then be pushed out of engagement with the transmitting gear 50due to the transverse movement of the catch and the action of the camsurface 93. The transmitting gear 50 will then be rotated due to theaction of spring 24 on sprocket wheel 36 and pinion contact gear 48. Thedriver gear 46 of the siren 42 will then be rotatedby the transmittinggear 50, thus sounding the alarm.

Since, from the foregoing, the construction and advantages of the devicemay be readily understood, further explanation is believed to beunnecessary.

However, since numerous modifications will readily occur to thoseskilled in the art after a consideration of the foregoing specificationand accompanying drawings, it is not intended to limit the invention tothe exact construction I determined temperature is reached; temperatureresponsive means for releasing said catch comprising a plate havingapertures adapted to selectively align with said catch, said catch beingpositioned adjacent one side of said plate, and magnetic meanspositioned adjacent the other side of said plate, said magneticmeansurging said catch to disengage saidmember of said gear train when saidaperture is in alignment with said catch.

2. The structure of claim 1 wherein said apertures comprise elongatedarcuate slots.

3. The structure of claim 2 wherein said catch comprises a disk of adiameter not greater than the width of said slots.

4. The structure of claim 1 including a shaft and a housing, said shaftbeing journaled in said housing, said magnetic means being secured tosaid housing, said plate being secured to said shaft.

5. In a fire alarm including a sounding device, a gear train operatingsaid sounding device, spring means for actuating said gear train, acatch engaging one member of said gear train fOr holding said gear trainagainst rotation until a predetermined temperature is reached;temperature responsive means for releasing said catch comprising a platehaving apertures adapted to selectively align with said catch, saidcatch being positioned adjacent one side of said plate, and magneticmeans positioned adjacent the other side of said plate, said magneticmeans urging said catch to disengage said member of said gear train whensaid aperture is in alignment with said catch, said catch comprising adisk.

JOHN SFREDDO.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,102,451 Stevens July '7, 19141,405,251 Anderson Jan. 31, 1922 2,371,511 Faux Dec. 12, 1940 FOREIGNPATENTS Number Country Date 700,032 Germany Dec. 12, 1940

